What was the evolutionary survival trait shared by all successful early hominids? select one: a. completely upright posture b. intelligence and ability to adapt c. opposable thumbs d. continuous fertility?

The correct answer is option b, that is, intelligence and tendency to adapt.  

The humans like animals, which walked upright were called hominids. It is considered that the earliest hominids lived about 4.4 million years ago in the humid forests of Southern and Eastern Africa.  

These species, known as Australopithecus, are considered to have been about 3 to 5 feet in length, and possibly fed on fruits, leaves, and the leftovers of dead animals. There is a strong proof that they utilized bones and sticks to help them in defending themselves and for digging purposes. This shows that they were intelligent and had to the tendency to adapt.  

the answer is b: 1.4 km/hr